Past criticisms to the contrary, methodological individualism in the social sciences is neither trivial nor obviously false. In the style of Weber's sociology, it restricts the ultimate explanatory repertoire of social science to agents' reasons for action. Although this restriction is not obviously false, it ought not to be accepted, at present, as a regulative principle. It excludes, as too far-fetched to merit investigation, certain hypotheses concerning the influence of objective interests on large-scale social phenomena. And these hypotheses, in fact, (...) merit empirical consideration. The attractiveness of methodological individualism as a regulative principle depends on two independent confusions, the conflation of an agent's reasons for action with the beliefs, needs, desires, or goals which are the reasons why he acted as he did, and the identification of explaining a phenomenon and describing its causes. (shrink)